A popular approach to monothematic delusions in the recent literature has been to argue that monothematic delusions involve broadly rational responses to highly unusual experiences. Campbell (2001) calls this the empiricist approach to monothematic delusions, and argues that it cannot account for the links between meaning and rationality. In place of empiricism, Campbell offers a rationalist account of monothematic delusions, according to which delusional beliefs are understood as Wittgensteinian framework propositions. We argue that neither Campbell's attack on empiricism nor his rationalist alternative to empiricism is successful.